Mr(BaSO4) = 137 + 32 + 16*4 = 233
Mr(Al(OH)3) = 27 + 16*3 + 1*3 = 78
Mr(Na2SO4) = 23*2 + 32 + 16*4 = 142
Mr(BaSO4) = 137 + 32 + 16*4 = 233
Mr(Al(OH)3) = 27 + 16*3 + 1*3 = 78
Mr(Na2SO4) = 23*2 + 32 + 16*4 = 142